Resolve "Synchrotron object string representation"

Description

By the way, this is created using a merge request template. Synchrotron, Optics, and Particle objects now have a proper repr and str methods.

Types of changes

What types of changes does your code introduce? Put an x in the boxes that apply.

• Bug fix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)
• Breaking change (fix or feature that would cause existing functionality to not work as expected)
• Documentation Update (if none of the other choices apply)
• Test coverage update

Related Issue

If suggesting a new feature or change, please discuss it in an issue first.

• New feature # (18)

Checklist:

Go over all the following points, and put an x in all the boxes that apply. If you're unsure about any of these, don't hesitate to ask. We're here to help!

• I have performed a self-review of my own code
• Code is formatted properly with yapf and isort
• Code follows the style guidelines of this project
• Code is commented where appropriate
• Documentation is updated with newest changes
• My changes generate no new warnings
• Tests for the new feature were added and they pass
• New and existing unit tests pass locally with new changes